This dissertation examines the careers and lives of white and American Indian women teachers who taught at the first federal off-reservation Indian boarding school, the Carlisle Indian Industrial School, 1875-1933. It analyzes the ways teachers responded to federal Indian educational policies of the late nineteenth and early twentieth centuries that were designed to assimilate Native Americans into modern America. These federal policies attempted to solve ‘the Indian problem’ by creating a curriculum that was crafted to rid Indian people of their cultures and languages, extinguish tribal ties to land, and weaken familial and community relationships. The first two chapters introduce the study and explore the evolution of the school’s first teacher, Sarah Mather, and her impact on Army Captain Richard Henry Pratt who would later go on to create the Carlisle Indian School and staff its classrooms. The third chapter examines the civilization and citizenship curriculum at Carlisle and teacher’s daily work of assimilation inside the classroom. The characteristics and motivations of white and American Indian teachers is the topic of the fourth chapter. This chapter also analyzes the benefits white and Native American teachers derived from their work, including the ways they used the prominence of the school to benefit themselves professionally. The fifth chapter explores the relationships teachers created and maintained with students and the ways some teachers used these relationships to attempt to more thoroughly carry out federal policies. The sixth chapter examines how American Indian teachers both accommodated important aspects of federal Indian educational policies in their work and lives but also, when needed, used the school system they themselves had been educated in to advocate for students and their families. This historical analysis reveals that many white women teachers at Carlisle either reproduced federal policies, fully embracing their new status as agents of the state or, dispirited by the male dominated Bureau of Indian Affairs, passively accommodated federal policies, accepted their paychecks and bid their time until retirement. Native teachers, however, more often resisted federal policies of cultural extinction by advocating for students and their families. While American Indian teachers at Carlisle accepted the idea that Native people had to assimilate, they sought to have a role in defining the contours of that process and, in their work and lives, modeled for Native children how to retain important aspects of their cultural identity, redefining what it meant to be a federal Indian school teacher.